High radiosensitivity in the conifer Norway spruce (Picea abies) due to lesscomprehensive mobilisation of protection and repair responses compared to the radiotolerant Arabidopsis thaliana
Authors: Bhattacharjee, P., Blagojevic, D., Lee, Y., Gillard, G. B., Gronvold, L., Hvidsten, T. R., Sandve, S. R., Lind, O. C., Salbu, B., Brede, D. A., Olsen, J. E.
The study compared early protective, repair, and stress responses to chronic gamma irradiation in the radiosensitive conifer Norway spruce (Picea abies) and the radiotolerant Arabidopsis thaliana. Norway spruce exhibited growth inhibition, mitochondrial damage, and higher DNA damage at low dose rates, while Arabidopsis maintained growth, showed minimal organelle damage, and activated DNA repair and antioxidant genes even at the lowest dose rates. Transcriptomic analysis revealed that the tolerant species mounts a robust transcriptional response at low doses, whereas the sensitive species only responds at much higher doses.
The study investigates the altered timing of the core circadian oscillator gene ELF3 in wheat compared to Arabidopsis, revealing that dawn-specific expression in wheat arises from repression by TOC1. An optimized computational model integrating experimental expression data and promoter architecture predicts that wheat’s circadian oscillator remains robust despite this shift, indicating flexibility in plant circadian network design.
Revisiting the Central Dogma: the distinct roles of genome, methylation, transcription, and translation on protein expression in Arabidopsis thaliana
Authors: Zhong, Z., Bailey, M., Kim, Y.-I., Pesaran-Afsharyan, N., Parker, B., Arathoon, L., Li, X., Rundle, C. A., Behrens, A., Nedialkova, D. D., Slavov, G., Hassani-Pak, K., Lilley, K. S., Theodoulou, F. L., Mott, R.
The study combined long‑read whole‑genome assembly, multi‑omics profiling (DNA methylation, mRNA, ribosome‑associated transcripts, tRNA abundance, and protein levels) in two Arabidopsis thaliana accessions to evaluate how genomic information propagates through the Central Dogma. Codon usage in gene sequences emerged as the strongest predictor of both mRNA and protein abundance, while methylation, tRNA levels, and ribosome‑associated transcripts contributed little additional information under stable conditions.
The study used comparative transcriptomics to examine how Fusarium oxysporum isolates with different lifestyles on angiosperms regulate effector genes during infection of the non‑vascular liverwort Marchantia polymorpha. Core effector genes on fast core chromosomes are actively expressed in the bryophyte host, while lineage‑specific effectors linked to angiosperm pathogenicity are silent, and disruption of a compatibility‑associated core effector alters the expression of other core effectors, highlighting conserved fungal gene networks across plant lineages.
The Global Wheat Full Semantic Organ Segmentation (GWFSS) dataset
Authors: Wang, Z., Zenkl, R., Greche, L., De Solan, B., Bernigaud Samatan, L., Ouahid, S., Visioni, A., Robles-Zazueta, C. A., Pinto, F., Perez-Olivera, I., Reynolds, M. P., Zhu, C., Liu, S., D'argaignon, M.-P., Lopez-Lozano, R., Weiss, M., Marzougui, A., Roth, L., Dandrifosse, S., Carlier, A., Dumont, B., Mercatoris, B., Fernandez, J., Chapman, S., Najafian, K., Stavness, I., Wang, H., Guo, W., Virlet, N., Hawkesford, M., Chen, Z., David, E., Gillet, J., Irfan, K., Comar, A., Hund, A.
The Global Wheat Dataset Consortium released a comprehensive semantic segmentation dataset (GWFSS) of wheat organs across developmental stages, comprising 1,096 fully annotated images and 52,078 unannotated images from 11 institutions. Models based on DeepLabV3Plus and Segformer were trained, with Segformer achieving ≈90% mIoU for leaves and spikes but lower precision (54%) for stems, while also enabling weed exclusion and discrimination of necrotic, senescent, and residue tissues.
Impaired methyl recycling induces substantial shifts in sulfur utilization in Arabidopsis
Authors: Tremblay, B. J.-M., Adeel, S. A., Saechao, M., Dong, Y., Andrianasolo, E., Steele, J. M., Traa, A., Yogadasan, N., Waduwara-Jayabahu, I., Katzenback, B. A., Hell, R., Wirtz, M., Moffatt, B. A.
Reduced activity of methylthioadenosine (MTA) nucleosidase causes MTA over‑accumulation in reproductive tissues, leading to lowered cysteine, methionine, and S‑adenosylmethionine levels and altered sulfur and energy metabolism. These metabolic disturbances trigger misregulation of cell‑cycle progression, widespread down‑regulation of developmental genes, and genome‑wide changes in DNA methylation patterns, highlighting the extensive role of MTA recycling in plant growth and methyl‑index maintenance.
The study generated a high-quality genome assembly for Victoria cruziana and used comparative transcriptomics to identify anthocyanin biosynthesis genes and their transcriptional regulators that are differentially expressed between white and light pinkish flower stages. Differential expression of structural genes (VcrF3H, VcrF35H, VcrDFR, VcrANS, VcrarGST) and transcription factors (VcrMYB123, VcrMYB-SG6_a, VcrMYB-SG6_b, VcrTT8, VcrTTG1) correlates with the observed flower color change.
RNA‑seq of 328 wheat lines using a pan‑genome reference uncovered over 20,000 additional transcripts beyond the Chinese Spring genome and enabled construction of a pan‑gene eQTL regulatory atlas. Multi‑omics integration identified 231 high‑confidence candidate genes influencing 34 agronomic traits and powdery mildew resistance, with functional validation showing 80% of candidates affecting trait phenotypes via an EMS mutant library.
Arabidopsis REM transcription factors and GDE1 shape the DNA methylation landscape through the recruitment of RNA Polymerase IV transcription complexes.
Authors: Wu, Z., Xue, Y., Wang, S., Shih, Y.-H., Zhong, Z., Feng, S., Draper, J., Lu, A., Sha, J., Li, L., Wohlschlegel, J., Wu, K., Jacobsen, S. E.
The study identifies four Arabidopsis REM transcription factors (VDD, VAL, REM12, REM13) that bind specific DNA sequences and, together with GDE1, recruit RNA polymerase IV to produce 24‑nt siRNAs that direct DNA methylation at designated loci. Loss of GDE1 causes Pol IV complexes to relocalize to sites bound by REM8, indicating that REM proteins provide sequence‑specific cues for epigenetic patterning.
The study reveals that a set of REPRODUCTIVE MERISTEM (REM) transcription factors, termed RIMs, are essential for directing RNA‑directed DNA methylation (RdDM) to CLSY3 targets in a sex‑specific manner in Arabidopsis reproductive tissues. Disruption of RIM DNA‑binding domains or their target motifs abolishes RdDM at these loci, demonstrating that genetic cues can guide de novo methylation patterns.